The Body Mass
Index (BMI) Calculation
The BMI
calculation is the World Health Organizations standard for measuring
whether sedentary individuals are underweight, overweight or obese.
Despite the
fact that he BMI calculation does not take into account factors such as
frame size and muscularity, or for varying proportions of muscle, fat,
bone & cartilage, and water weight, the BMI categories are
generally regarded as a satisfactory measurement tool, and have been
used by the W.H.O. as the standard for recording obesity statistics
since the early 1980s.
The following
are common definitions of BMI categories:
|
Starvation:
|
less
than 15
|
|
Anorexic:
|
less
than 17.5
|
|
Underweight:
|
less
than 18.5
|
|
Ideal:
|
18.5
to 25
|
|
Overweight:
|
from
25 to 30
|
|
Obese:
|
from
30 to 40
|
|
Morbidly
Obese:
|
greater
than 40
|
How Many Calories
Do You Need?
Three primary
components make up your body's energy requirement.
Adding
these three components together is the most accurate way of determining
how many calories your body requires each day to maintain your current
weight at your current activity level.
The Basal
Metabolic Rate (BMR) Calculation - Most of
the body's energy, about 60-70%, goes to supporting the ongoing
metabolic work of the body's cells. This includes such activities as
heart beat, respiration and maintaining body temperature. Basal
metabolic rate is the number of calories your body burns at rest,
taking into account all of your life support functions.
Energy
expended during physical activity - Our calculator above uses a very
simple method to roughly estimate calorie expenditure for increasing
activity levels, and factors that into the BMR calculation. The
algorithm for this calculation is actually fairly complex. The Fatsense
Fitness Calculator utilizes
one of the most reliable methods
for calculating calories burned during physical activity, the
Metabolic Energy (MET) Method.
The Thermic
Effect of Food (TEF) - The last
component to calculate for your daily calorie requirement has to do
with your body's management of food. The increase in energy required to
digest food is referred to as the Thermic Effect of Food (TEF) and it's
simple to determine:
TEF
= total kcals consumed x 10%
After you
have calculated your Basal Metabolic Rate, and added the energy
required for your level of physical activity, simply add up all those
calories, add to this 10% of that sum and you have your total
calorie requirement for that day.
Once
you've established your baseline, you can lower your calorie intake to
lose weight, or increase lean muscle by increasing protein, calories
and exercise. By changing the variables and re-calculating your
baseline, you can adjust your program to best suit your goals.
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